The present invention relates to tampons, and more particularly to a tampon wetness detection system signaling a remote reporting device of the wetness of the tampon.
Present-day users of tampons have to use a destructive test in order to ascertain whether a tampon has residual absorbent capacity remaining. That is, the tampon must be removed to see if it is full, and even if it is not full, the tampon usually is not reinserted. Generally a user removes a tampon before it has reached its capacity in order to prevent an accident wherein the capacity of the tampon is exceeded and the excess menses flows unimpeded from the vagina to soil the user's clothing.
In tampons as presently known a determinative criteria frequently used for removing a tampon is time elapsed since insertion. The time elapsed criteria for changing tampons is not satisfactory for several reasons, e.g., the menstrual flow rate varies throughout the menstruating period and much adsorbent capacity of tampons is wasted due to the tendency to change before an accident occurs.
The flow variation throughout the period causes problems as to how long to wear a tampon because a user cannot establish a definite time period for which the absorbent capacity within a tampon is sufficient. Therefore, she is in a quandary as to how long to wear specific tampons during days of heavy flow as contrasted to days of light flow.
A correlation between tampon performance during light flow versus heavy flow is difficult for the user to make. Thus, since the user would rather be safe than sorry, she frequently removes a tampon before the absorbent capacity of the tampon has been reached and wastes much of the product she had purchased.
The prior tampon art tried to make tampons bigger and more absorbent so that a user would not have to change as often. But the user would still waste a portion of the absorbent capacity she had purchased in that she still was not willing to have an accident.
Therefore, bigger tampons provided a longer wearing time but did not approach the problem of fully using the absorbent capacity within a tampon without soiling her clothing. In rare cases, should a user forget to remove a tampon a life threatening infection may develop.
These problems associated with the use of tampons were recognized and solutions proposed.
U.S. Pat. No. 3,794,024 to Kokx discloses an indicator in contact with the absorbent body of a catamenial device. The indicator "reads" the wetness of the absorbent body and translates the wetness into a signal which can be sensed without removing, the catamenial device. Change in temperature (heat generation or consumption by dissolving material) or color formation are used as indicators.
However, both these approaches suffer limitations. The amount of heat generated or consumed depends upon the reaction rate. If it is slow, heat dissipation will prevent sensing the signal. Color indication, on the other hand, requires an intimate inspection by the user.
U.S. Pat. No. 5,361,627 to Levesque discloses a method and apparatus for measuring the capillary attraction developed at a surface of an absorbent body intended to be used in a sanitary article such as a sanitary napkin, a diaper, a urinary pad, an adult brief, a tampon or a wound dressing, among others. The apparatus comprises a probe of fritted glass providing an array of capillary passageways in fluid communication with the interior of a closed cell completely filled with liquid. A pressure sensor mounted to the closed cell observes the liquid pressure therein. When the probe is placed in contact with the absorbent body, the capillary attraction exerted on liquid in the probe capillaries by the porous network of the absorbent body is transmitted through the liquid medium in the cell to the pressure sensor. The pressure data thus obtained reflects the state of dryness of the absorbent body surface. The capillary attraction measurement is made with no appreciable transfer of liquid toward the absorbent body to avoid altering its condition.
While the invention by Levesque is suitable of measuring the capillary attraction developed at the surface of externally used absorbent bodies, it is not at all applicable for a vaginaly inserted tampon. Furthermore, a wetness test using the disclosed device requires intimacy.
U.S. Pat. No. 5,468,236 to Everhart discloses a disposable feminine care product which includes a chemically reactive means having an end point adapted to provide a visual indication of the presence of a substance in mammalian bodily excrement. However, a wetness test using the disclosed device requires intimacy.
Similar solutions which include visual indication of the wetness of the tampon are disclosed in U.S. Pat. Nos. 4,192,311 to Felfoldi; and 5,217,444 to Schoenfeld.
Visual indications of wet diapers are disclosed in 3,952,746 to Summers; 4,231,370 to Mroz; 4,287, 153 to Towsend; 4,327,731 to Powell; 4,507,121 to Leung; 4,705,513 to Sheldon et al.; 4,738,674 to Todd et al.; and 5,197,958 to Howell.
Conductivity based indication of wet diapers are disclosed in U.S. Pat. Nos. 5,266,928 and 5,469.145 to Johnson; 4,205,672 to Dvorak; 4,484,573 to Yoo; 4,704,108 to Okada: 4,796,014 to Chia; and 5,568,128 to Nair. U.S. Pat. Nos. 4,356,818 to Macias et al.; 4,653,491 and 4,754,264 to Okada et al. disclose remote wetness informing device using an oscillator and receiver.
There is thus a widely recognized need for, and it would be highly advantageous to have, a tampon wetness detection system devoid of the above limitations.